Keratin fibre dye composition containing pyrazolopyrimidinoxo compounds, use thereof as dye couplers, and dyeing methods

ABSTRACT

The present invention relates to a composition for dyeing keratin fibres, in particular human hair, containing, in a medium which is suitable for dyeing:as coupler, at least one compound of formulaor one of the addition salts with an acid, withR1 denotes, in particular, hydrogen, alkyl, aryl, a heterocycle, halogen,R2 denotes, in particular, hydrogen, halogen, alkoxy, aryloxy, acyloxy, arylthio, alkylthio,R3 has the same meanings as those for R1,Za and Zb, which are different, denote C=O or CR4, with R4 having the same meanings as R1;and at least one oxidation base.

The invention relates to a composition for the oxidation dyeing ofkeratin fibres, in particular human hair, containing at least onepyrazolopyrimidinoxo compound as coupler and at least one oxidationbase.

It is known to dye keratin fibres, and in particular human hair, withdye compositions containing oxidation dye precursors, in particularortho- or para-phenylene diamines, ortho- or para-aminophenols, andheterocyclic compounds, which are generally referred to as oxidationbases. Oxidation dye precursors, or oxidation bases, are colourless orweakly coloured compounds which, when combined with oxidizing products,can give rise to coloured compounds and dyes by a process of oxidativecondensation.

It is also known that the shades obtained with these oxidation bases canbe varied by combining them with couplers or colour modifiers, thelatter being chosen in particular from aromatic meta-diamines,meta-aminophenols, meta-diphenols and certain heterocyclic compoundssuch as indole compounds.

The variety of molecules used as oxidation bases and couplers allows awide range of colours to be obtained.

The so-called “permanent” coloration obtained by means of theseoxidation dyes must moreover satisfy a certain number of requirements.Thus, it must have no toxicological drawbacks, it must be able to allowshades to be obtained in the desired intensity and it must show goodresistance to external agents (light, bad weather, washing, waving,permanent-waving, perspiration, rubbing).

The dyes must also be able to cover grey hair and, lastly, they must beas unselective as possible, i.e. they must allow only the smallestpossible colour differences to be obtained along the length of the samekeratin fibre, which may, indeed, be differently sensitized (i.e.damaged) between its tip and its root.

The Applicant has now discovered that it is possible to obtain novel,powerful, unselective and particularly resistant dyes, which are capableof giving rise to intense colorations in varied shades, by usingpyrazolopyrimidinoxo compounds as couplers in the presence of anoxidation base.

This discovery forms the basis of the present invention.

The subject of the invention is a composition for dyeing keratin fibres,and in particular human keratin fibres such as the hair, characterizedin that it comprises, in a medium which is suitable for dyeing.

as coupler, at least one pyrazolopyrimidinoxo compound of formula (I),or one of the addition salts thereof with an acid.

in which:

R₁ represents: a hydrogen atom; a linear or branched C₁-C₂₀ alkylradical optionally substituted with 1 or 2 radicals R chosen from thegroup consisting of halogen, nitro, cyano, hydroxyl, alkoxy, aryloxy,amino, alkylamino, acylamino, carbomoyl, sulphonamido, sulphamoyl,imido, alkylthio, arylthio, aryl, alkoxycarbonyl, acyl; an aryl radical(such as phenyl or naphthyl) optionally substituted with 1 or 2 radicalsR as defined above; a 5- or 6-membered heterocycle having at least onenitrogen, oxygen or sulphur atom (such as pyridyl, quinolyl, pyrrolyl,morpholyl, furyl, tetrahydrofuryl, pyrazolyl, triazolyl, tetrazolyl,thiazolyl, oxazolyl, imidazolyl or thiadiazolyl) optionally substitutedwith 1 or 2 radicals R as defined above;

when R₁ denotes an alkyl radical, an aryl radical or a 5- or 6-memberedheterocycle (defined above),

it can be linked to the carbon atom of the ring via an oxygen, nitrogenor sulphur atom (in this case, R₁ becomes XR₁ with X═O, NH, S);

R₁ can also denote a halogen atom (such as bromine, chlorine orfluorine); an acyl radical; a sulphonyl radical; a sulphinyl radical; aphosphonyl radical; a carbamoyl radical; a sulphamoyl radical; a cyanoradical; a siloxy radical; an amino radical; an acylamino radical; anacyloxy radical; a carbamoyloxy radical; a sulphonamide radical; animide radical; a ureido radical; a sulphamoylamino radical; analkoxycarbonylamino radical; an aryloxycarbonylamino radical; analkoxycarbonyl radical; an aryloxycarbonyl radical; a carboxyl radical;

R₂ represents: a hydrogen atom; a halogen atom such as bromine, chlorineor fluorine; an acetylamido group; an alkoxy radical (such as, forexample: methoxy, ethoxy, propyloxy, benzyloxy, methoxyethoxy,phenoxyethoxy, 2-cyanoethoxy, phenethyloxy, p-chlorobenzyloxy,methoxyethylcarbamoylmethoxy); an aryloxy radical (such as, for example:phenoxy, 4-methoxylphenoxy, 4-nitrophenoxy, 4-cyanophenoxy,4-methanesulphonamidophenoxy, 4-methanesulphonylphenoxy,3-methylphenoxy, 1-naphthyloxy); an acyloxy radical (such as, forexample: acetoxy, propanoyloxy, benzoyloxy, 2,4-dichlorobenzoyloxy,ethoxyalkyloxy, pyruvyloyloxy, cinnamoyloxy, myristyloxy); an arylthioradical (such as, for example: phenylthio, 4-carboxyphenyltio,4-methanesulphonylphenylthio); an alkylthio radical (such as, forexample: methylthio, ethylthio, propylthio, butylthio, 2-cyanoethylthio,benzylthio, phenethylthio, 2-(diethylamino)ethylthio, ethoxyethylthio,phenoxyethylthio); a heteroarylthio radical (such as, for example:5-phenyl-2,3,4,5-tetrazolylthio, 2-benzothiazolylthio): a heteroaryloxyradical (such as, for example: 5-phenyl-2,3,4,5-tetrazolyloxy,2-benzothiazolyloxy); a thiocyano radical; anN,N-diethylthiocarbonylthio radical; a dodecyloxythiocarbonylthioradical; a benzenesulphonamido radical; an N-ethyltoluenesulphonamidoradical; a pentafluorobutanamido radical; a2,3,4,5,6-pentafluorobenzamido radical; a p-cyanophenylureido radical;an N,N-diethylsulphamoylamino radical; a pyrazolyl radical; animidazolyl radical; a triazolyl radical; a tetrazolyl radical; abenzimiazolyl radical; a 1-benzyl-5-ethoxy-3-hydantoinyl

radical; a 1-benzyl-3-hydantoinyl radical;5,5-dimethyl-2,4-dioxo-3-oxazolidinyl; a 2-oxy-1,2-dihydro-1-pyridylradical; an alkylamido; an arylamido; a radical NR^(III)R^(IV) withR^(III) and R^(IV), which may be identical or different, representing aC₁-C₄ alkyl, a hydroxyalkyl; a carboxyl; or an alkoxycarboxylic radical;

R₃ has the same meanings mentioned as those mentioned for the radicalR₁;

Z_(a) and Z_(b) are different and represent a C═O group or a carbon atombearing a radical R₄ having the same meanings as those mentioned for theradical R₁;

and at least one oxidation base.

The addition salts with an acid for the compounds of the invention canbe chosen in particular from hydrochlorides, hydrobromides, tertrates,tosylates, benzenesulphonates, sulphates, lactates and acetates.

Among the radicals R₁ of formula (I) defined above, the preferredradicals are chosen from the group consisting of:

a hydrogen atom; a linear or branched C₁-C₄ alkyl; a phenyl; a phenylsubstituted with a halogen atom; a C₁-C₄ alkyl, a C₁-C₄ alkoxy, a nitrogroup, an amino group, a trifluoromethyl group or a C₁-C₄ alkylaminogroup; a benzyl radical; a benzyl radical substituted with a halogenatom, a C₁-C₄ alkoxy, a nitro group, an amino group, a trifluoromethylgroup; a C₁-C₄ alkylamino, a heterocycle chosen from thiophene, furanand pyridine; a trifluoromethyl radical; a radical(CH₂)_(p)—X—(CH₂)₄—OR′ where p and q are integers, which may beidentical or different, between 1 and 3, R′ represents H or methyl and Xdenotes an oxygen atom or a group NR″ with R″ denoting hydrogen ormethyl; a C₁-C₄ hydroxylalkyl; a C₁-C₄ aminoalkyl; a C₁-C₄ alkylamino; aC₁-C₄ dialkylamino; a phenyloxycarbonyl; cyano; an arylamino; an alkoxyradical chosen from methoxy, ethoxy, phenoxy; a halogen chosen fromchlorine, bromine, fluorine; a carboxyl group; a (C₁-C₄) alkoxycarbonyl.

Among the radicals R₁ of formula (I) defined above, the radicals moreparticularly preferred as chosen from the group consisting of: hydrogen;an alkyl chosen from methyl, ethyl, isopropyl, tert-butyl; a halogenchosen from fluorine and chlorine; phenyl; toluyl; 4-chlorophenyl;4-methoxyphenyl; 3-methoxyphenyl; 2-methoxyphenyl; benzyl; a heterocyclechosen from pyridyl, furyl and thienyl; trifluoromethyl; hydroxymethyl;aminomethyl; methoxy or ethoxy; methylamino or ethylamino ordimethylamino; carboxyl; methoxycarbonyl or ethoxycarbonyl; cyano.

Even more particularly, the preferred radicals R₁ are chosen from thegroup consisting of: hydrogen; methyl; ethyl; phenyl; toluyl;4-chlorophenyl; 4-methoxyphenyl; benzyl; trifluoromethyl; chloro; amethoxy or ethoxy radical; a carboxyl radical; methylamino ordimethylamino; cyano.

Among the radicals R₂ of formula (I) defined above, the preferredradicals are chosen from the group consisting of:

a hydrogen atom; a C₁-C₄ alkoxy; phenoxy; phenoxy substituted with ahalogen atom, a C₁-C₄ alkyl, a carboxyl, a trifluoromethyl group; anacyloxy radical; benzyloxy; C₁-C₄ alkylthio; phenylthio; phenylthiosubstituted with a halogen atom, a C₁-C₄ alkyl, a carboxyl, atrifluoromethyl group; a C₁-C₄ alkylamido; phenylamido; a radicalNR^(III)R^(IV) with R^(III) and R^(IV), which may be identical ordifferent, representing a C₁-C₄ alkyl, a C₁-C₄ hydroxyalkyl; a carboxyl;a C₁-C₄ alkoxycarboxylic radical.

Among the radicals R₂ of formula (I) defined above, the radicals moreparticularly preferred are chosen from the group consisting of:

hydrogen; chlorine or bromine; methoxy or ethoxy; phenoxy;4-methylphenoxy; acyloxy; benzyloxy; methylthio or ethylthio;phenylthio; 4-methylphenylthio; 2-tert-butylphenylthio; acetamido;phenylacetamido; dimethylamino; diethylamino; ethylmethylamino;(β-hydroxyethyl)methylamino.

Even more particularly, the preferred radicals R₂ are chosen from thegroup consisting of: hydrogen; chlorine; ethoxy; phenoxy; benzyloxy;acyloxy; acetamido; dimethylamino.

Among the radicals R₃ and R₄ of formula (I) defined above, the preferredradicals are chosen from the group consisting of:

a hydrogen atom; a linear or branched C₁-C₄ alkyl optionally substitutedwith a hydroxyl or amino; a phenyl; a phenyl substituted with one or twogroups chosen from a halogen, a C₁-C₄ alkyl, a C₁-C₄ alkoxy; a hydroxyl;a carboxyl, a nitro group, a C₁-C₄ alkylthio, a methylenedioxy group, anamino group, a trifluoromethyl group or a C₁-C₄ alkylamino; a benzylradical; a benzyl radical substituted with a halogen atom, a methyl orisopropyl, methoxy; a C₁-C₄ hydroxyalkyl; a C₁-C₄ aminoalkyl; a C₁-C₄alkylaminoalkyl; an amino radical; a C₁-C₄ alkylamino radical, a halogensuch as chlorine or bromine; a trifluoromethyl.

Among the radicals R₃ and R₄, the preferred radicals are chosen from thegroup consisting of: hydrogen; C₁-C₄ alkyl (such as methyl; ethyl;isopropyl); halogen (such as chlorine, bromine); amino; C₁-C₄ alkylamino(such as methylamino, ethylamino or dimethylamino); an aryl radical(such as phenyl, toluyl, 2-, 3-or 4-chlorophenyl, 3- or 4-hydroxyphenyl,3- or 4-aminophenyl, 3- or 4-methoxyphenyl, 4-trifluoromethylphenyl);benzyl; hydroxymethyl or hydroxyethyl; aminomethyl or aminoethyl;trifluoromethyl.

Even more particularly, the preferred radicals R₃ and R₄ are chosen fromthe following radicals:

hydrogen, methyl, ethyl, isopropyl, trifluoromethyl, chlorine, amino,methylamino, ethylamino, phenyl, 4-chlorophenyl, 4-methoxyphenyl.

Among the preferred compounds of the invention of formula (I), mentionmay be made of those chosen from the group consisting of:

(i) pyrazolo[1,5-a]pyrimidin-7-oxo compounds of formula:

(ii) pyrazolo[1,5-a]pyrimidin-5-oxo compounds of formula:

in which the radicals R₁, R₂, R₃ and R₄ have the same meanings as thosementioned above.

As examples of compounds of formula (Ia), mention may be made of thosefor which:

R₁ denotes hydrogen, methyl, ethyl, chlorine, phenyl, methoxy,trifluoromethyl, carboxyl or cyano;

R₂ denotes hydrogen, chlorine or ethoxy;

R₃ and R₄ respectively denote: hydrogen and hydrogen; hydrogen andmethyl; methyl and hydrogen; hydrogen and amino; chlorine and methyl;chlorine and amino; carboxyl and methyl; hydrogen and trifluoromethyl,or carboxyl and hydrogen.

As compounds of formula (Ia) above, mention may be made mostparticularly of:

2-carboxy-5-methylpyrazolo(1,5-a)pyrimidin-7-one,

2-ethylthio-5-methylpyrazolo[1,5-a]pyrimidin-7-one,

2-methyl-5-trifluoromethylpyrazolo[1,5-a]pyrimidin-7-one,

2-phenyl-5-trifluoromethylpyrazolo[1,5-a]pyrimidin-7-one,

2-carboxy-5-trifluoromethylpyrazolo[1,5-a]pyrimidin-7-one,

2-ethylthio-5-trifluoromethylpyrazolo[1,5-a]-pyrimidin-7-one,

5-trifluoromethylpyrazolo[1,5-a]-pyrimidin-7-one,

5-methylpyrazolo[1,5-a]pyrimidin-7-one,

6-carboxypyrazolo[1,5-a]pyrimidin-7-one,

6-carboxy-2-methylpyrazolo[1,5-a]pyrimidin-7-one,

6-carboxy-2-phenylpyrazolo[1,5-a]pyrimidin-7-one,

6-carboxy-2-ethylthiopyrazolo[1,5-a]pyrimidin-7-one,

2,6-dicarboxypyrazolo[1,5-a]pyrimidin-7-one,

2-methyl-6-ethoxycarbonylpyrazolo[1,5-a]pyrimidin-7-one,

2-(2′-furyl)-6-methylpyrazolo[1,5-a]pyrimidin-7-one,

2-(2′-thienyl)-6-methylpyrazolo[1,5-a]pyrimidin-7-one,

3-ethoxycarbonyl-6-methylpyrazolo[1,5-a]pyrimidin-7-one,

2-methyl-5-methoxymethylpyrazolo[1,5-a]pyrimidin-7-one,

2-tert-butyl-5-trifluoromethylpyrazolo[1,5-a]pyrimidin-7-one, and theaddition salts thereof with an acid.

As examples of compounds of formula (Ib), mention may be made of thosefor which R₁, R₂, R₃ and R₄ have the same meanings as those mentioned inthe examples of compounds of formula (Ia) defined above.

As compounds of formula (Ib) above, mention may be made mostparticularly of:

pyrazol[1,5-a]pyrimidin-5-one,

2-methylpyrazolo[1,5-a]pyrimidin-5-one,

2,7-dimethylpyrazolo[1,5-a]pyrimidin-5-one,

2-phenylpyrazolo[1,5-a]pyrimidin-5-one,

2-ethylthiopyrazolo[1,5-a]pyrimidin-5-one,

2-carboxypyrazolo[1,5-a]pyrimidin-5-one,

7-aminopyrazolo[1,5-a]pyrimidin-5-one,

7-amino-2-methylpyrazolo[1,5-a]pyrimidin-5-one,

7-amino-2-phenylpyrazole[1,5-a]pyrimidin-5-one,

7-amino-2-ethylthiopyrazolo[1,5-a]pyrimidin-5-one,

7-amino-2-carboxypyrazolo[1,5-a]pyrimidin-5-one,

and the addition salts thereof with an acid.

The compounds of the present invention and their processes are describedin patent application EP-A-304,001.

Their synthetic intermediates are described in patent applicationsEP-A-591,103, WO 92/04349 and EP-A-320,764 and in the followingpublications:

C. Musante, Gazetta Chim. Ital. 73, 355, 1943;

H. Dorn, Liebigs Ann. Chem. 707, 141, 1967;

H. Dorn, Liebigs Ann. Chem. 717, 118, 1968;

P. Arnold, Angew. Chem. Int. Ed., 13, 205, 1974;

K. Takahashi, Synthesis, 794, 1985;

C. B. Vicentini, Il Farmaco, 47, (7, 8), 1021, 1992;

K. S. Hartke, J. Am. Chem. Soc., 81, 2456, 1959;

C. B. Vicentini, J. Het. Chem., 26, 797, 1989.

The compound(s) of formula (I) preferably represent(s) from 0.0005 to12% by weight approximately relative to the total weight of the dyecomposition, and even more preferably from 0.005 to 6% by weightapproximately relative to this weight.

The nature of the oxidation base(s) which can be used in the dyecomposition according to the invention is not critical. This or theseoxidation bases is(are) preferably chosen from para-phenylenediamines,bis(phenyl)alkylenediamines, para-aminophenols, ortho-aminophenols andheterocyclic bases, and the addition salts thereof with an acid.

Among the para-phenylenediamines which can be used as oxidation bases inthe dye composition according to the invention, mention may be made inparticular of the compounds corresponding to formula (II) below:

R₅ represents a hydrogen atom, a C₁-C₄ alkyl, C₁-C₄ monohydroxyalkyl,C₂-C₄ polyhydroxyalkyl or (C₁-C₄)alkoxy(C₁-C₄)alkyl radical,

R₆ represents a hydrogen atom of a C₁-C₄ alkyl, C₁-C₄ monohydroxyalkylor C₂-C₄ polyhydroxyalkyl radical,

R⁷ represents a hydrogen atom, a halogen atom such as a chlorine atom,or a C₁-C₄ alkyl, sulpho, carboxyl, C₁-C₄ monohydroxyalkyl or C₁-C₄hydroxyalkoxy radical,

R₈ represents a hydrogen atom or a C₁-C₄ alkyl radical.

In formula (II) above, and when R₇ is other than a hydrogen atom, thenR₅ and R₆ preferably represent a hydrogen atom and R₇ is preferablyidentical to R₈, and when R₇ represents a halogen atom, then R₅, R₆ andR₈ preferably represent a hydrogen atom.

Among the para-phenylenediamines of formula (II) above, mention may bemade more particularly of para-phenylenediamine, para-toluylenediamine,2-isopropyl-para-phenylenediamine,2-β-hydroxyethyloxy-para-phenylenediamine2,6-diethyl-para-phenylenediamine,4-amino-1-(β-methoxyethyl)aminobenzene and2-chloro-para-phenylenediamine, and the addition salts thereof with anacid.

Among the bis(phenyl)alkylenediamines which can be used as oxidationbases in the dye composition according to the invention, mention may bemade in particular of the compounds corresponding to formula (III)below, and the addition salts thereof with an acid:

in which:

Q₁ and Q₂, which may be identical or different, represent a hydroxylradical or a radical NHR₁₂ in which

R₁₂ represents a hydrogen atom of a C₁-C₄ alkyl radical,

R₉ represents a hydrogen atom or a C₁-C₄ alkyl, C₁-C₄ monohydroxyalkyl,C₂-C₄ polyhydroxyalkyl or C₁-C₄ aminoalkyl radical in which the aminoresidue may be substituted,

R₁₀ and R₁₁, which may be identical or different represent a hydrogen orhalogen atom or a C₁-C₄ alkyl radical,

W represents a radical taken from the group consisting of the followingradicals

in which n is an integer between 0 and 8 inclusive and m is an integerbetween 0 and 4 inclusive.

Among the bis(phenyl)alkylenediamines of formula (III) above, mentionmay be made more particularly ofN,N′-bis(β-hydroxyethyl)-N,N′-bis-(4′-aminophenyl)-1,3-diamino-2-propanol,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl)ethylenediamine,N,N′-bis(β-hydroxyethyl)-N,N′-bis(4-aminophenyl) tetramethylenediamine,and N,N′-bis(ethyl)-N,N′-bis (4′-amino-3′-methylphenyl) ethylenediamine,and the addition salts thereof with an acid.

Among these bis(phenyl)alkylenediamines of formula (III),N,N′-bis(β-hydroxyethyl)-N,N′-bis(4′-aminophenyl) -1,3-diaminopropanolor one of the addition salts thereof with an acid are particularlypreferred.

Among the para-aminophenols which can be used as oxidation bases in thedye composition according to the invention, mention may be made inparticular of the compounds corresponding to formula (IV) below, and theaddition salts thereof with an acid.

in which:

R₁₃ represents a hydrogen atom or a C₁-C₄ alkyl, C₁-C₄ monohydroxyalkyl,(C₁-C₄)alkoxy(C₁-C₄)alkyl or C₁-C₄ aminoalkyl radical, R₁₄ represents ahydrogen or fluorine atom or a C₁-C₄ alkyl, C₁-C₄ monohydroxyalkyl,C₂-C₄ polyhydroxyalkyl, C₁-C₄ aminoalkyl, cyano(C₁-C₄)alkyl or(C₁-C₄)alkoxy(C₁-C₄)alkyl radical, it being understood that at least oneof the radicals R₁₃ or R₁₄ represents a hydrogen atom.

Among the para-aminophenols of formula (IV) above, mention may be mademore particularly of para-aminophenyl, 4-amino-3-methylphenol,4-amino-3-fluorophenol, 4-amino-4-hydroxymethylphenol,4-amino-2-methylphenol, 4-amino-2-hydroxymethylphenol,4-amino-2-methoxymethylphenol, 4-amino-2-aminomethylphenol and4-amino-2-(β-hydroxyethylaminomethyl)phenol, and the addition saltsthereof with an acid.

Among the ortho-aminophenols which can be used as oxidation bases in thedye composition according to the invention, mention may be made inparticular of 2-aminophenol, 2-amino-1-hydroxy-5-methylbenzene,2-amino-1-hydroxy-6-methylbenzene and 5-acetamido-2-aminophenol, and theaddition salts thereof with an acid.

Among the heterocyclic bases which can be used as oxidation bases in thedye composition according to the invention, mention may be made inparticular of pyridine derivatives, pyrimidine derivatives and pyrazolederivatives, and the addition salts thereof with an acid.

Among the pyridine derivatives, mention may be made more particularly ofthe compounds described, for example, in GB patents 1,026,978 and1,153,196, such as 2,5-diaminopyridine, and the addition salts thereofwith an acid.

Among the pyrimidine derivatives, mention may be made more particularlyof compounds described, for example, in German patent DE 2,359,399 orJapanese patents JP 88-169,571 and JP 91-333,495, such as2,4,5,6-tetraaminopyrimidine and 4-hydroxy-2,5,6-triaminopyrimidine, andthe addition salts thereof with an acid.

Among the pyrazole derivatives, mention may be made more particularly ofthe compounds described in patents DE 3,843,892 and DE 4,133,957 andpatent applications WO 94/08969 and WO 94/08970, such as4,5-diamino-1-methylpyrazole, 3,4-diaminopyrazole and1-(4′-chlorobenzyl)-4,5-diaminopyrazole and the addition salts thereofwith an acid.

According to the invention, the oxidation base(s) preferablyrepresent(s) from 0.0005 to 12% by weight approximately relative to thetotal weight of the dye composition, and even more preferably from 0.005to 6% by weight approximately relative to this weight.

The dye composition according to the invention can also contain one ormore additional couplers other than the compounds of formula (I) and/orone or more direct dyes, so as to vary the shades obtained with theoxidation bases or to enrich the shades with glints.

The additional couplers which can be used in the composition accordingto the invention can be chosen from the couplers used conventionally inoxidation dyeing, and among which mention may be made in particular ofmeta-phenylenediamines, meta-aminophenols, meta-diphenols andheterocyclic couplers such as, for example, indole derivatives andindoline derivatives, and the addition salts thereof with an acid.

These couplers can be chosen in particular from 2-methyl-5-aminophenol,5-N-(β-hydroxyethyl)amino-2-methylphenol, 3-aminophenol,1,3-dihydroxybenzene, 1,3-dihydroxy-2-methylbenzene,4-chloro-1,3-dihydroxybenzene, 2,4-diamino-1-(β-hydroxyethyloxy)benzene,2-amino-4-(β-hydroxyethylamino)-1-methoxybenzene, 1,3-diaminobenzene,1,3-bis(2,4-diaminophenoxy)propane, sesamol, α-naphthol,6-hydroxyindole, 4-hydroxyindole, 4-hydroxy-N-methylindole and6-hydroxyindoline, and the addition salts thereof with an acid.

When they are present, these additional couplers preferably representfrom 0.0005 to 5% by weight approximately relative to the total weightof the dye composition, and even more preferably from 0.005 to 3% byweight approximately relative to this weight.

The addition salts with an acid for the oxidation base(s) and/or for theadditional couplers which can be used in the dye composition of theinvention are chosen in particular from the hydrochlorides,hydrobromides, sulphates, tartrates, lactates and acetates.

The medium which is suitable for dyeing for the support) generallyconsists of water or of a mixture of water and at least on organicsolvent for dissolving the compounds which would not be sufficientlywater-soluble. As organic solvents, mention may be made, for example, ofC₁-C₄ lower alcohols, such as ethanol and isopropanol; glycerol; glycolsand glycol ethers such as 2-butoxyethanol, propylene glycol, propyleneglycol monomethyl ether, diethylene glycol monoethyl ether andmonomethyl ether, and aromatic alcohols such as benzyl alcohol orphenoxyethanol, similar products and mixtures thereof.

The solvents can be present in proportions preferably of between 1 and40% by weight approximately relative to the total weight of the dyecomposition, and even more preferably between 5 and 30% by weightapproximately.

The pH of the dye composition in accordance with the invention isgenerally between 3 and 12. It can be adjusted to the desired valueusing acidifying or basifying agents usually used to dye keratin fibres.

Among the acidifying agents, mention may be made, by way of example, ofinorganic or organic acids such as hydrochloric acid, orthophosphoricacid, carboxylic acids such as tartaric acid, citric acid and lacticacid, and sulphonic acids.

Among the basifying agents, mention may be made, by way of example, ofaqueous ammonia, alkaline carbonates, alkanolamines such as mono-, di-and triethanolamines and derivatives thereof, sodium hydroxide,potassium hydroxide and the compounds of formula (IV) below:

in which R is a propylene residue optionally substituted with a hydroxylgroup or a C₁-C₄ alkyl radical, R₁₅, R₁₆, R₁₇ and R₁₈, which may beidentical or different, represent a hydrogen atom or a C₁-C₄ alkyl orC₁-C₄ hydroxyalkyl radical.

The dye composition according to the invention can also contain variousadjuvants conventionally used in compositions for dyeing the hair, suchas anionic, cationic, nonionic, amphoteric or zwitterionic surfactantsor mixtures thereof, anionic, cationic, nonionic, amphoteric orzwitterionic polymers or mixtures thereof, inorganic or organicthickeners, antioxidants, penetration agents, sequestering agents,fragrances, buffers, dispersing agents conditioners such as, forexample, silicones, film-forming agents, preserving agents andopacifiers.

Needless to say, the person skilled in the art will take care to selectthe optional complementary compound(s) mentioned above, such that theadvantageous properties intrinsically associated with the dyecomposition according to the invention are not, or not substantially,adversely affected by the addition(s) envisaged.

The dye composition according to the invention can be in various forms,such as in the form of liquids, creams or gels or in any other formwhich is suitable for dyeing keratin fibres, and the particular humanhair.

The subject of the invention is also the use of thepyrazolopyrimidinoxos of formula (I) above, as couplers, in combinationwith at least one oxidation base base for the oxidation dyeing ofkeratin fibres, in particular human keratin fibres such as the hair.

Another subject of the invention is a process for the oxidation dyeingof keratin fibres, and in particular human keratin fibres such as thehair, using the dye composition as defined above.

According to this process, at least one dye composition as defined aboveis applied to the fibres, the colour being developed at acidic, neutralor alkaline pH using an oxidizing agent which is added to the dyecomposition only at the moment of use, or which is present in anoxidizing composition that is applied simultaneously or sequentially ina separate manner.

According to a particularly preferred embodiment of the dyeing processaccording to the invention, the dye composition described above ismixed, at the moment of use, with an oxidizing composition containing,in a medium which is suitable for dyeing, at least one oxidizing agentthat is present in an amount which is sufficient to develop acoloration. The mixture obtained is then applied to the keratin fibresand is left to stand on them for 3 to 50 minutes approximately,preferably 5 to 10 minutes approximately, after which the fibres arerinsed, washed with shampoo, rinsed again and dried.

The oxidizing agent present in the oxidizing composition as definedabove can be chosen from the oxidizing agents conventionally used forthe oxidation dyeing of keratin fibres, and among which mention may bemade of hydrogen peroxide, urea peroxide, alkali metal bromates andpersalts such as perborates and persulphates. Hydrogen peroxide isparticularly preferred.

The pH of the oxidizing composition containing the oxidizing agent asdefined above is such that after mixing with the dye composition, the pHof the resulting composition applied to the keratin fibres preferablyranges between 3 and 12 approximately and even more preferably between 5and 11. It is adjusted to the desired value using acidifying orbasifying agent usually used to dye keratin fibres and as defined above.

The oxidizing composition as defined above can also contain variousadjuvants conventionally used in compositions for dyeing the hair and asdefined above.

The composition which is finally applied to the keratin fibres can be invarious forms, such as in the form of liquids, creams or gels or in anyother form which is suitable for dyeing keratin fibres, and inparticular human hair.

Another subject of the invention is a dyeing “kit” or multi-compartmentdevice or any other multi-compartment packaging system, in which a firstcompartment contains the dye composition as defined above and a secondcompartment contains an oxidizing composition as defined above.

These devices can be equipped with means which allow the desired mixtureto be delivered onto the hair, such as the devices described in patentFR-2,586,913 in the name of the Applicant.

EXAMPLES Examples 1 to 3 of Dyeing in Alkaline Medium

Examples 1 2 3 2,7-Dimethylpyrazolo[1,5-a]- 0.490 0.490 —pyrimidin-5-one (coupler) 2,5-Dimethylpyrazolo[1,5-a]- — — 0.490pyrimidin-7-one (coupler) Para-phenylenediamine 0.324 0.324 0.324(oxidation base) Common dye support No. 1 No. 1 No. 1 Demineralizedwater qs 100 g 100 g 100 g

NB: The 2,7 -dimethylpyrazolo[1,5-a]pyrimidin-5-one was preparedaccording to the process described in patent application EP-A-304,001,and the 2,5-dimethylpyrazolo[1,5-a]pyrimidin-7-one is sold under thetrade name KM 00085 by the company Maybridge

Common dye support No. 1:

Benzyl alcohol  2.0 g Polyethylene glycol containing 6 mol  3.0 g ofethylene oxide Ethanol  20.0 g (C₈-C₁₀) Alkylpolyglucoside as an  6.0 gaqueous solution containing 60% active material, buffered with ammoniumcitrate, sold under the name Oramix CG110 by the company Seppic Aqueousammonia containing 20% NH₃  10.0 g Sodium metabisulphite 0.228 gSequestering agent qs

At the moment of use, the dye composition of Example 1 above was mixedwith an equal weight of 20-volumes hydrogen peroxide solution (6% byweight); each of the dye compositions of Examples 2 and 3 above wasmixed with an equal weight of an aqueous ammonium persulphate solutionat a concentration of 6×10⁻³ mol %.

Each mixture obtained was applied for 30 minutes to locks ofpermanent-waved or non-permanent-waved natural grey hair containing 90%white hairs, at a rate of 10 g per 1 g of hair. After rinsing, washingwith a standard shampoo and drying, the locks were dyed in the shadesfeatures in Table 1 below:

TABLE 1 Shade obtained on Shade obtained permanent-waved on natural greygrey hair pH of the hair containing containing 90% Example mixture 90%white hairs white hairs 1 9.9 Iridescent Slightly red iridescent 2 10.1Iridescent Iridescent bright red 3 9.8 Slightly golden Slightly goldenvery light very light blond blond

Example 4 of Dying in Neutral Medium

The following dye composition, in accordance with the invention, wasprepared:

2,5-Dimethylpyrazolo[1,5-a]- 0.490 g pyrimidin-7-onePara-phenylenediamine 0.324 g Benzyl alcohol  2.0 g Polyethylene glycol6 EO  3.0 g Ethanol  20.0 g (C₈-C₁₀) Alkylpolyglucoside as an aqueous 6.0 g solution containing 60% active material buffered with ammoniumcitrate, sold under the name Oramix CG110 by the company SeppicK₂HPO₄/KH₂PO₄ (1.5M/1M) buffer  10.0 g Sodium metabisulphite 0.228 gSequestering agent qs

At the moment of use, the dye composition of Example 4 above was mixedwith an equal weight of an aqueous ammonium persulphate solution at aconcentration of 6×10⁻³ mol %.

The mixture obtained had a pH of 7.2, and was applied for 30 minutes tolocks of natural grey hair containing 90% white hairs, at a rate of 10 gper 1 g of hair. After rinsing, washing with a standard shampoo anddrying, the locks were dyed in a slightly golden very light blond shade.

Examples 5 to 7 of Dyeing in Alkaline Medium

Examples 5 6 7 2-Methyl-5-methoxymethyl- 0.579 — —pyrazolo[1,5-a]pyrimidin-7-one (coupler) 2-tert-Butyl-5- — 0.777 —trifluoromethylpyrazolo- [1,5-a]pyrimidin-7-one (coupler)2-Methyl-6-ethyoxycarbonyl- — — 0.663 pyrazolo[1,5-a]pyrimidin-7-one(coupler) 1,3-Dimethyl-4,5-diamino- 0.597 — 0.597 pyrazoledihydrochloride (oxidation base) N,N-Bis(β-hydroxyethyl)-para- — 0.807 —phenylenediamine dihydro- chloride (oxidation base) Common dye supportNo. 1 No. 1 No. 1 Demineralized water qs 100 g 100 g 100 g

NB: The 2-methyl-5-methoxymethylpyrazolo[1,5-a]pyrimidin-7-one and2-methyl-6-ethoxycarbonylpyrazolo[1,5-a]pyrimidin-7-one are sold,respectively under the trade names KN 00739 and KM 00318 by the companyMaybridge.

Common dye support No. 1:

This is identical to the one used for Examples 1 to 3 above.

At the moment of use, the dye compositions of Examples 5 and 6 abovewere mixed with an equal weight of 20-volumes hydrogen peroxide solution(6% by weight); the dye composition of Example 7 above was mixed with anequal weight of an aqueous ammonium persulphate solution at aconcentration of 6×10⁻³ mol %.

Each mixture obtained was applied for 30 minutes to locks ofpermanent-waved or non-permanent-wave natural grey hair containing 90%white hairs, at a rate of 10 g per 1 g of hair. After rinsing, washingwith a standard shampoo and drying, the locks were dyed in the shadesfeatured in Table 2 below:

TABLE 2 Shade obtained on Shade obtained permanent-waved on natural greygrey hair pH of the hair containing containing 90% Example mixture 90%white hairs white hairs 5 9.9 Very light Light rosewood rosewood 6 9.9Bottle green Bottle green 7 9.8 Light golden Light golden blond blond

What is claimed is:
 1. A process for the oxidation dyeing of keratinfibers comprising (a) applying to the keratin fibers an effective amountfor dyeing of at least one dyeing composition; (b) developing color atacidic, neutral, or alkaline pH in the presence of an oxidizing agentwhich is added to said at least one dyeing composition at the same timesaid at least one dyeing composition is applied, or which is present inan oxidizing composition that is applied: (i) separately from said atleast one dyeing composition at the same time that said at least onedyeing composition is applied to the fibers, or (ii) sequentially withsaid at least one dyeing composition, wherein said at least one dyeingcomposition comprises, in a medium which is suitable for dyeing, atleast one oxidation base and at least one coupler chosen frompyrazolopyrimidinoxo compounds of formula (I) and acid addition saltsthereof:

in which: R₁ and R₂ are each independently chosen from a hydrogen atom;a linear or branched C₁-C₂₀ alkyl radical, unsubstituted or substitutedwith 1 or 2 radicals R; an aryl radical, unsubstituted or substitutedwith 1 or 2 radicals R; and a 5- or 6-membered heterocycle having atleast one nitrogen, oxygen or sulphur atom, unsubstituted or substitutedwith 1 or 2 radicals R; wherein R is chosen from halogen, nitro, cyano,hydroxyl, C₁-C₄ alkyl, haloalkyl, carboxyl, alkoxy, aryloxy, amino,alkylamino, acylamino, carbamoyl, sulphonamido, sulphamoyl, imido,alkylthio, arylthio, aryl, alkoxycarbonyl, and acyl groups; with theproviso that when R₁ is a linear or branched C₁-C₂₀ alkyl radical, anaryl radical or a 5- or 6-membered heterocycle, R₁ may be linked to thecarbon atom of the ring via an oxygen, nitrogen or sulphur atom, suchthat R₁ is XR₁ wherein X is O, NH, or S; R₁ and R₃ can each alsoindependently be chosen from a halogen atom; an acyl radical; asulphonyl radical; a sulphinyl radical; a phosphonyl radical; ahaloalkyl radical; a carbamoyl radical; a sulphamoyl radical; a cyanoradical; a siloxy radical; an amino radical; an acylamino radical; anacyloxy radical; an alkoxy radical; an aryloxy radical; an alkylthioradical; a carbamoyloxy radical; a sulphonamide radical; an imideradical; a ureido radical; a sulphamoylamino radical; analkoxycarbonylamino radical; an aryloxycarbonylamino radical; analkoxycarbonyl radical; an aryloxycarbonyl radical; and a carboxylradical; R₂ is chosen from a hydrogen atom; a halogen atom; anacetylamido group; an alkoxy radical; an aryloxy radical; an acyloxyradical; an arylthio radical; an alkylthio radical; a heteroarylthioradical; a heteroaryloxy radical; a thiocyano radical; anN,N-diethylthiocarbonylthio radical; a dodecyloxythiocarbonylthioradical; a benzenesulphonamido radical; an N-ethyltoluenesulphonamidoradical; a pentafluorobutanamide radical; a2,3,4,5,6-pentafluorobenzamido radical; a p-cyanophenylureido radical;an N,N-diethylsulphamoylamino radical; a pyrazolyl radical; animidazolyl radical; a triazolyl radical; a tetrazolyl radical, abenzimidazolyl radical; a 1-benzyl-5-ethoxy-3-hydantoinyl radical; a1-benzyl-3-hydantoinyl radical; 5,5-dimethyl-2,4-dioxo-3-oxazolidinyl a2-oxy-1,2-dihydro-1-pyridyl radical; an alkylamido; an arylamido; and aradical NR^(III)R^(IV) wherein R^(III) and R^(IV) are independentlychosen from a C₁-C₄ alkyl, a hydroxyalkyl, a carboxyl, or analkoxycarboxylic radical; wherein all of said radicals may besubstituted or unsubstituted, and Z_(a) and Z_(b) are different fromeach other and represent a C═O group or CR₄ wherein R₄ independently hasthe same definition as given above for R₁.
 2. A process according toclaim 1, wherein said keratin fibers are human hair.
 3. A processaccording to claim 1, wherein the oxidizing agent is hydrogen peroxide,urea peroxide, an alkali metal bromate, or persalt.
 4. A processaccording to claim 3, wherein the oxidizing agent is a persalt, andfurther wherein said persalt is a perborate or persulphate.
 5. A processaccording to claim 1, wherein the oxidizing agent is hydrogen peroxide.6. A process according to claim 1, wherein before said applying step,said at least one dyeing composition is mixed with an oxidizingcomposition comprising, in a medium suitable for dyeing, at lest oneoxidizing agent in an amount sufficient to develop coloration; aftersaid developing step, said mixture is left on said keratin fibers for atime ranging from about 3 to about 50 minutes; and said keratin fibersare rinsed, washed, rinsed again and dried.
 7. A process according toclaim 6, wherein said time ranges from about 5 to about 30 minutes.